Red Blood Cell Distribution Width (RDW ) as a Predictor ofIn-Hospital Mortality in COVID-19 Patients; a Cross Sec-tional Study

Red blood cell distribution width (RDW ) has been introduced as a predictive factor for mortalityin several critical illnesses and infectious diseases. This study aimed to assess the possible relationship betweenRDW on admission and COVID-19 in-hospital mortality.

This cross-sectional study was performedusing the Isfahan COVID-19 registry. Adult confirmed cases of COVID-19 admitted to four hospitals affiliatedwith Isfahan University of Medical Sciences in Iran were included. Age, sex, O2 saturation, RDW on admission,Intensive Care Unit admission, laboratory data, history of comorbidities, and hospital outcome were extractedfrom the registry. Cox proportional hazard regression was used to study the independent association of RDWwith mortality.

4152 patients with the mean age of 61.1 ± 16.97 years were included (56.2% male).597 (14.4%) cases were admitted to intensive care unit (ICU) and 477 (11.5%) cases died. The mortality rate ofpatients with normal and elevated RDW was 7.8% and 21.2%, respectively (OR= 3.1, 95%CI: 2.6-3.8), which re-mained statistically significant after adjusting for age, O2 saturation, comorbidities, and ICU admission (2.03,95% CI: 1.68-2.44). Moreover, elevated RDW mortality Hazard Ratio in patients who were not admitted to ICUwas higher than ICU-admitted patients (3.10, 95% CI: 2.35-4.09 vs. 1.47, 95% CI: 1.15-1.88, respectively).

The results support the presence of an association between elevated RDW and mortality in patientswith COVID-19, especially those who were not admitted to ICU. It seems that elevated RDW can be used as apredictor of mortality in COVID-19 cases.